MIRO Operating Authority and Affiliations

MIRO operates under the authority of the Mercer Island Emergency Preparedness organization headed by Mercer Island Police Officer Jennifer Franklin who is the Mercer Island Emergency Preparedness Officer. Mercer Island Emergency Preparedness Website.  MIRO operates under the aegis of the ARRL Western Washington Section Amateur Radio Emergency Service (ARES).  We report directly to the Mercer Island Emergency Operations Center EOC and, as directed, to the King County EOC.


Emergency Practice Net: Second Thursday of the month at 7:00 PM

The net is conducted on the MIRO VHF repeater frequency of 147.160 MHz positive offset tone 146.2 Hz. The check-ins are by assigned neighborhood region.  After announcements the net shifts to the UHF repeater 440.150 MHz positive offset tone 103.5 for a role call of those who have checked in on VHF.  The purpose is to practice shifting frequencies.

In the event of a repeater failure, the net will switch to the simplex frequency of 147.440 MHz.

Monthly Meeting: Third Thursday of the month at 7:00 PM

The MIRO meetings are typically held at Mercer Island Fire Station 91 (North Fire Station), 3030 78th AVE SE, Mercer Island WA 98040.

All MIRO members, prospective hams, and visitors are encouraged to attend.  The monthly MIRO Newsletter will specify meeting location and subject.


MIRO is a group of amateur radio operators who volunteer their time to provide back-up communications for the City of Mercer Island and its Police and Fire Departments in the event of natural or man-made emergencies.


Ron Elsoe, Former Mercer Island Public Safety Director and Bob Farmer, N7SJW, founded this organization in 1993 under the name Mercer Island Amateur Radio Emergency Net. They sent out a questionnaire to the all of the FCC licensed amateur radio operators on the Island and asked them to respond for an initial roster. From this initial response the group has continued to grow and now has over 70 members.

Current and Planned Infrastructure

MIRO has a radio room at the Mercer Island City Hall located adjacent to the MI Police Department Operations Center. MIRO also has a back up radio room located in the Mercer Island Community and Event Center at Mercerview (MICEC). Additionally there are VHF and UHF voice radios at the north and south fire stations on Mercer Island.

Voice communications are facilitated through the use of VHF and UHF radio repeaters located on a shared communication tower located at the Mercer Island water reservoir on the highest point on Mercer Island. These repeaters accept low-level signals from radios around the island and repeat them so that they are clearly audible on most parts of the island as well as on many off island locations.

MIRO also provides for email and other digital communications capability on two VHF and two UHF gateway frequencies. These digital communications allow computer-to-computer connections for those MIRO amateurs with digital equipment. When all other internet service is down, as long as the emergency generators are powering the gateways, email can be sent anywhere in the world.   Additionally with the appropriate software and HF radio capability an operator can communicate with email without the gateways in operation.  The services are called WINLINK and WINMOR.

Repeaters and Operating Frequencies

2 Meter Repeater (VHF) 147.160 MHz, +0.6 MHz offset, 146.2 Hz tone
70 Centimeter Repeater (UHF) 440.150 MHz, +5 MHz offset, 103.5 Hz tone
2 Meter Simplex 147.440 MHz
2 Meter Simplex 146.600 MHz


MIRO Winlink Support

SYSOP: Michael Roessler –  KG7DFG@WINLINK.org,  Cell phone (206) 960-1936

Effective November 2017


Frequency (MHz) Data Rate (baud) Callsign-SSID Antenna
Primary Nodes
145.030 1200 W7MIR-10 Vertical
430.825 1200 W7MIR-11 Vertical
Auxiliary (fallback) Nodes
145.790 1200 WA6PXX-10 Vertical
440.825 1200 WA6PXX-10 Vertical

Station Addresses

Winlink Address Location Phone Number
W7MIR@Winlink.org EOC radio room at City Hall (206) 275-7630
W7MIR-7@Winlink.org Radio room at CCMV (Community Center at Mercerview) (206) 275-7875

Note: Winlink transmitted or destined messages require “//WL2K” in the subject line to avoid being screened out by the Winlink Spam filter.

MIRO File Downloads

These are public files that you are free to download and redistribute.

  • To view, click the link in the File column.
  • To download, right-click the link in the File column and choose “Save Target As…” from the pop-up menu.
File Description Date
Cascadia Rising 2016 scenario.pdf Description of the Cascadia Rising 2016 exercise scheduled for June 7th through 10th. Current
MIRO Fact Sheet.pdf A one-page summary describing the MIRO organization. June, 2016
MIRO Overview.pdf Slideshow that describes amateur radio and MIRO’s role in the Mercer Island emergency plan. Feb 2017
MIRO Winlink Manual Manual for operating WINLINK 11.11.17
RMS Express 1.pdf

RMS Express 2.pdf

RMS Express 3.pdf

WINLINK and its use



April, 2016

courtesy of


King County ARES Master Frequency 3.28.14.pdf Current King County ARES frequency list. March, 2014
Radiogram.pdf ARRL Radiogram form. September, 2003
RadiogramUse.pdf Instructions for using the ARRL Radiogram form. September, 2003
Emergency Prep 2011.pdf Emergency Preparedness Overview. April, 2011
New Ham Orientation.pdf Presentation Deck for New Hams. Feb 2017

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